This invention generally pertains to measuring devices. More specifically, the present invention relates to a matching type cutter tip measuring device.
The invention is particularly applicable to conical single lip or tip V-shaped engraving cutters. However, it will be appreciated by those skilled in the art that the invention has broader application and may also be adapted for use in many other environments, e.g. cutter tip measurement of other types of cutters.
Heretofore, conventional measuring devices for cutters have included expensive optical comparators which necessitated that the cutter be removed from a cutter grinder during the inspection process. One type of comparator is a projection type comparator which works by projecting, with an extremely accurate lens, an enlarged (20X) image of the cutter onto a screen consisting of a reticle or grid containing various scales for measuring tip width, cutter angles, etc. Projection comparators are, however, exceptionally expensive and also have the disadvantage that the cutter must be removed from a cutter grinder during the resharpening process in order to measure the tip width.
Another cutter measuring alternative is the use of a cutter measuring microscope. This device is essentially a microscope with a built-in reticle for measuring cutter widths. This instrument is also quite expensive and also requires that the cutter be removed from the cutter grinder for measurement.
A much less expensive instrument for measuring cutter width is a conventional pocket comparator. This device consists of a low power magnifier having a graduated glass or plastic reticle on its bottom allowing one to visually approximate cutter sizes as well as the width of engraved grooves. Although this device is quite ecomonical, the minimum measuring graduations, which may be 0.005 inches, are difficult to read. Also, optical parallax can cause misleading measurements.
A further problem with all of the measuring devices mentioned is that it is difficult, at best, to directly measure a cutter tip since the angle of the tip coupled with the cutter tip clearance causes the cutter tip to measure smaller than it actually cuts.
Accordingly, it has been considered desirable to develop a new and improved cutter measuring device which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.